code: def norm_rgb(r, g, b):
      """
      Normalise RGB components so the most intense (unless all
      are zero) has a value of 1.
      """
      greatest = max([r, g, b])
  
      if greatest > 0:
          r /= greatest
          g /= greatest
          b /= greatest
      return (r, g, b)
  
file_path: vispy/examples/demo/gloo/galaxy/galaxy_specrend.py
imports: import math
label_desc: Use image node_id 8 for calling a global function with example usage: norm_rgb(r, g, b) and returns: r,  g,  b